July 1, 2011

By Kevin

Comments Off on IIS 7.5 and Compression

Categories: Compression, IIS, JavaScript

Tags: , ,

IIS 7.5 and Compression

I recently configured compression on a IIS 7.5 website, but it took a few steps.  I was not able to find all the steps required in one place so I thought I would post them here.

The first step is to make sure static compression is enabled in your ApplicationHost.config file like so:

<httpCompression directory="%SystemDrive%inetpubtempIIS Temporary Compressed Files" minFileSizeForComp="0">
<scheme name="gzip" dll="%Windir%system32inetsrvgzip.dll" />
<staticTypes><add mimeType="text/*" enabled="true" />
<add mimeType="message/*" enabled="true" />
<add mimeType="application/javascript" enabled="true" />
<add mimeType="*/*" enabled="false" />

Next we must change the javascript mime type in the ApplicationHost.config to:

<remove fileExtension=".js" />
<mimeMap fileExtension=".js" mimeType="text/javascript" />

The last step is to run an appcmd command that tells IIS to compress all pages not just pages accessed twice within 10 seconds, which is the default.

%windir%system32inetsrvappcmd.exe set config
-section:system.webServer/serverRuntime -frequentHitThreshold:1

Now we have static compression enabled in IIS 7.5.